Cancer in children is not common. And although this is something to be thankful for, it can make things a little more challenging for researchers. This is simply because if fewer people have a particular type of cancer then there are fewer people to take part in clinical trials.
To help overcome this hurdle, Cancer Research UK funds 20 childhood cancer clinical trial centres across Great Britain, linked together within the Children’s Cancer and Leukaemia Group (CCLG). Our scientists also collaborate with research groups around the world to run international trials into childhood cancers.
And today, we announced the opening of an international clinical trial into neuroblastoma – a rare type of childhood cancer.
The trial is a perfect example of how research can bring pioneering new treatments to children with cancer in the UK – and is based on some really exciting scientific discoveries…
A new way to tackle neuroblastoma
Around 100 children are diagnosed with neuroblastoma in the UK each year – most of whom are under the age of five. The cancer grows from nerve cells ‘left over’ from the development of the nervous system, and often starts in the abdomen.
About half of all children with the disease have a more aggressive form called high-risk neuroblastoma. It’s these children who will be taking part in the new trial, which is testing a type of immunotherapy – a catch-all term used to describe treatments that use the power and precision of the body’s own immune system to fight disease.
In the new trial, patients will be given a type of molecule called a monoclonal antibody. These are proteins produced in the lab that can stick to particular molecules on the surface of cells – in this case, molecules called GD2 antigens that are found on the surface of neuroblastoma cells.
The antibodies are injected directly into the patient’s bloodstream, where they travel around the body and eventually encounter the tumour, and stick to the GD2 antigens on the cancer cells.
Once the cancer cells are ‘labelled’ in this way, the body’s immune system can recognise them – and destroy them.
A similar technique to the one being tested in the new trial has already shown exciting results in a US study, and until now the treatment has only been available in America.
As in most trials, the US study compared the outcome for two groups of patients – one receiving the new treatment and one the standard treatment. But the new antibody treatment was so promising that the trial was modified so that all children participating ended up receiving it.
The treatment is designed to be used after a child has been treated with a combination of surgery, chemotherapy and radiotherapy. These standard treatments eliminate most of the cancer cells, and then the highly targeted antibody should – in theory – encourage the child’s immune system to mop up any that remain.
The new trial will split participants into two groups. One will receive the antibody alone, and the other the antibody and another molecule called a cytokine.
Cytokines are molecules produced by the cells of the immune system. They act as signals that can attract more immune cells to a particular area. The theory is that the extra cytokine will encourage the immune system to mount a more powerful attack against the neuroblastoma cells.
All participants in the modified US trial received the antibody with one of two different cytokines, so this new trial is the first time treatment with the antibody alone has been tested. The new trial aims to discover which approach gives the best outcome for patients.
The promise of immunotherapy
Immunotherapy is an area that’s been under intense research for over a decade, and has shown promise in treating other types of cancer. The breast cancer drug Herceptin is another example of a monoclonal antibody-based treatment.
But as Cancer Research UK’s chief clinician Professor Peter Johnson explained, ‘this is the first time an antibody has been taken into treatment for childhood cancer.’
And it spells good news for children with aggressive neuroblastoma. At our press conference, Great Ormond Street Hospital’s Dr Penelope Brock, the lead researcher on the trial, said the rapid launch of this trial in the UK was really fantastic news for patients. ‘Early results from the US trial found that children who received the immunotherapy treatment had less chance of the disease coming back two years later, compared with patients who did not receive the antibody.’
The new trial means that children in the UK now have access to what Dr Brock says is ‘possibly the biggest breakthrough in neuroblastoma for a very long time.’ However, she also sounded a note of caution, saying that longer term outcomes are still not known and so further international trials will be necessary.
For uncommon cancers like neuroblastoma, international trials are vital for to ensure that enough participants are included to give accurate results. This trial aims to recruit 2000 patients from across Europe, including about 160 children with high-risk neuroblastoma from the UK. The team are hoping that nearly all eligible children in the UK will take part in the trial and receive the new treatment – the first two participants are starting their treatment this week.
Committed to childhood cancer research
Cancer Research UK is the largest funder of research into children’s cancers in the UK – we spent over £9 million last year on research in this area. For this latest trial, we are paying not only the running costs but also the cost of manufacturing the new treatment. This is because the drug is so cutting-edge that no pharmaceutical companies (that would usually supply drugs for a clinical trial) are yet involved.
We have also funded many of the world’s most successful trials of children’s cancer treatments, and more than three quarters of children with cancer in the UK now survive. Back in the 1960s, only a quarter of children survived – a testament to how investment in scientific research can ultimately improve treatment and care.
Nell Barrie, Science Information Officer